HOG BPW transition question

[TigerDiver8]

I having been diving my HOG Singles BPW for over a year now and love it, although I am going to need doubles here for a short amount of time, solely to take a ton of pictures of 3 different wrecks at around 120 feet. If I go down with a single tank i wont have enough bottom time to take time and get the shots i need of each wreck. by the way the wrecks are in three different locations. So I wanted to do doubles to extend my deep dive bottom time. What is the best way to go about this in the cheapest way. Can i buy attachments or a side mount rig or anything besides buying a new back plate and wing? Otherwise I would just rent the gear for those dives.


Thank you and safe diving

 

[chrpai]

I think you need to be thinking training not gear. PADI AIR RDP for 120' is 13 minutes. Pushing the MOD a little bit, it's 20 minutes on 32%

Assuming even a somewhat higher then normal SAC of .75SCFM you're using 3.5CF per minute at 120'. You can easily do that profile on say single tank... say a 95, 100 or 120. With a better SAC rate you could do that dive on an AL80.

So available gas isn't really your constraint. NDL's are your constraint. And if you want to start getting into deco/TECH diving safely your going to want the training to do it. And from there you'll make a bunch of gear choices that probably aren't what you are thinking of right now.

 

[PfcAJ]

All you need is a new wing. 55ish pounds for big 8inch tanks (lp104s, hp119s, etc), 40ish pounds for 7 inch tanks (al80s, 72s, 85s and the like). Naturally another 1st stage, too. Your plate will work with doubles unless its one of those specialty single tank only things, which are rare.

also make sure you can swim up your rig from depth. Balanced rig and all that.

Thats it for gear.

 

[je76]

First and foremost if you are going to start diving doubles I suggest you seek out a mentor or an LDS to get some training on diving doubles. Most of the advice that you will get here, mine included, is insufficient to do what you are looking to do so find someone that can mentor and show you the safest way to dive with doubles.

The discussion of your NDL at 120' is very appropriate as I would imagine you would run out of NDL time before gas but only you would know that. Keep in mind as well that running down to the edge of your NDL (riding the "Oh" as it is sometimes called) can have its own hazards as well so don't use more gas in your doubles to run near decompression.

You will get as many opinions as there are divers here. I personally dive my doubles with a redundant source of lift either meaning the dual bladder on my wing or a dry suit. There are some that will say you should be able to swim your rig up and I am sure that works for them but I prefer a true redundancy. I personally use manifolded doubles because I like the ability to shut down and isolate as needed as well as access all my gas in an emergency. That being said a side mount rig would work although you would most likely still be looking at extra gear and training. You aren't just going to jump into side mount or independent doubles.

When I went to doubles my safety and the gear I needed was my primary focus not cost perse. I didn't want to get ripped off but also didn't want to be at 120' wishing I would have sprung the extra $200.00 for something that would have saved my life either. Deep diving with a camera requires some gear, training and experience, short cut that at your own peril.

 

[RJP]

Why do I have a strange feeling this thread will eventually be moved to "Incidents and Accidents"?

 

[chrpai]

So training aside....

You could buy a 1st/2nd regulator with a 40" hose and 2"SPG on a 6" hose and stage rigging kit for around $300 give or take. Less if used. You could then rent an AL80, put your rigging on it and sling it off your left d-rings. This would basically give you independent doubles.

 

[00wabbit]

You don't "need" those photos. You "want" them.

Don't let that idea of needing the shot get you killed or bent. If you really need a photo - try google images before you try doubles.

 

[corvettejoe]

I think you need to be thinking training not gear. PADI AIR RDP for 120' is 13 minutes. Pushing the MOD a little bit, it's 20 minutes on 32%

Assuming even a somewhat higher then normal SAC of .75SCFM you're using 3.5CF per minute at 120'. You can easily do that profile on say single tank... say a 95, 100 or 120. With a better SAC rate you could do that dive on an AL80.

So available gas isn't really your constraint. NDL's are your constraint. And if you want to start getting into deco/TECH diving safely your going to want the training to do it. And from there you'll make a bunch of gear choices that probably aren't what you are thinking of right now.

I'm going to agree with chrpai here... NDL will be your limiting factor on your dives. I've gotten nice long dives at deeper depths with single overfilled LP steel tanks, but then you get into deco at that point. I don't think doubles are going to do anything for you unless you're at shallower depths. And even then, you will eventually hit NDL limits at anything doubles would be useful for.

So training aside....

You could buy a 1st/2nd regulator with a 40" hose and 2"SPG on a 6" hose and stage rigging kit for around $300 give or take. Less if used. You could then rent an AL80, put your rigging on it and sling it off your left d-rings. This would basically give you independent doubles.

When back mounting, I regularly dive my HOG BP/Wing (32lb wing) with a large LP 108 (or LP85) and an AL80 clipped off on the side. The rig handles it with no problem at all. This is my usual lobstering setup. Sometimes I wear my monkey harness under it to bungee the stage to the side (al-la-sidemount). Just depends on my mood.

 

[Doc Harry]

chrpai is correct.

When someone starts asking questions like this, my response is that if you don't already know the answer then you need more training before attempting such a thing.

It's been said a million times, and I'll say it again: don't exceed the level of your training.